Thanks for the prompt reply. Yes, that was it. I forgot that internal state inside the archive may be changing after serialization. What about the private nature of get_library_version()? I can't invoke the method on a polymorphic_binary_iarchive because it's private, whereas it's public in a binary_archive. This isn't a big issue, I can certainly work around it, it's more of a personal curiosity. Thanks again, Anis "Robert Ramey" <ramey@rrsd.com> wrote in message news:g14420$86p$1@ger.gmane.org...

An archive can't be const as it is changed when something is serialized to it

try:

void foo(boost::archive::polymorphic_iarchive& ar) { ar >> boost::serialization::make_nvp("typeName", *typePtr); ... }

Robert Ramey

Anis wrote:

...

I'm seeing the following error when trying to serialize from a polymorphic_iarchive. I'm new to boost::serialization, so I was hoping somebody could shed some light on what I was doing wrong? I tried googling and searching the archives, but didn't find anything yet.

error C2678: binary '>>' : no operator found which takes a left-hand operand of type 'const boost::archive::polymorphic_iarchive' (or there is no acceptable conversion) c:\boost\include\boost-1_35\boost\archive\detail\interface_iarchive.hpp(62): could be 'Archive &boost::archive::detail::interface_iarchive<Archive>::operator

...

...

<const boost::serialization::nvp<T>>(const boost::serialization::nvp<T> &)'

The code in question is essentially: virtual void foo(const boost::archive::polymorphic_iarchive& ar) { ar >> boost::serialization::make_nvp("typeName", *typePtr); ... }

Also, it appears as though get_library_version() is private for polymorphic_iarchive_dispatch. I'm confused, isn't it public elsewhere? I was hoping to have access to it. I reckon there's a reason behind this, so I'm just curious as to why it's private.

Thanks!